Horizontal and large deviated wells are widely used for reservoir developments. Theoretically, horizontal wells should be able to produce at several times the rate of comparable vertical wells. In reality, the productivity of a horizontal well is often much less than its potential. The difference between the theoretical and the actual production in horizontal wells may be the result of a number of factors. For example, horizontal wells may have a non-uniform reservoir pressure distribution along the wellbore because horizontal wells tend to be drilled in producing fields, which have unevenly depleted regions. Horizontal wells also may encounter strong formation heterogeneity in reservoirs extending along relatively long wellbores. Horizontal wells also can suffer from formation damage incurred during drilling and from inadequate cleanup processes, particularly towards the tip of the wellbore. Water humps and gas traps also can occur along the tortuous, horizontal wellbore. The non-uniform pressure distribution, strong formation heterogeneity, uneven damage, water humps and gas traps lead to non-uniform production along boreholes of deviated, e.g. horizontal, wells. To improve the productivity of these wells, it is desirable to obtain detailed and non-uniformly distributed information along the wellbore.
Attempts have been made to test horizontal wells for well related limitations on production with the goal of correcting the problems to improve production. However, the available testing tends to be limited and relies on data collected at the heel of the well which generally is only an average of the entire horizontal wellbore section. As a result, any remedial treatment of the horizontal well typically has been performed in a blind fashion without precise knowledge of the areas, extent and type of damage along the horizontal well. Existing testing systems also fail to provide sufficient information in a short period of time. Furthermore, well testing generally is done as a preliminary procedure via, for example, pressure transient testing or production logging. After evaluation, remedial treatment is performed as a separate service during a separate trip downhole.